OnGUI is not being called

I was attempting to create a main menu, and after inputting a 3D Options Menu, OnGUI refused to be called, I suspected this when my fade-in code stopped working, however the exact same code in another level worked perfectly, it fades in and fades out. To test if OnGUI was actually being called I added a small Label to test it. It was not renderered.

function OnGUI(){

	//Debugging OnGUI (Because evidence inclines it's not being called)
	GUILayout.BeginArea(Rect(10,10,200,20));
	GUILayout.Label("OnGUI is being called");
	GUILayout.EndArea();	
	
	if(firstLoad){
		fadeTime = 2;
		alphaFadeValue -= Mathf.Clamp01(Time.deltaTime / fadeTime);
		
		GUI.color = Color(0,0,0,alphaFadeValue);
		GUI.DrawTexture(Rect(0,0,Screen.width, Screen.height),fadeTexture);
		
		if(alphaFadeValue <= 0){
			firstLoad = false;
			fadeTime = 0;
			alphaFadeValue = 0;
		}
	}
	
	if(isLoading){
		fadeTime = 2;
		alphaFadeValue += Mathf.Clamp01(Time.deltaTime / fadeTime);
		
		GUI.color = Color(0,0,0,alphaFadeValue);
		GUI.DrawTexture(Rect(0,0,Screen.width, Screen.height),fadeTexture);
		
		if(alphaFadeValue >= 1){
			fadeTime = 0;
			alphaFadeValue = 1;
			Application.LoadLevel("Level1");
		}

	}
		
}

As you can see, the very first bit of code should be working, but it does not show up. It was working fine up until now.

Code i’m using for attempting to start a new game;

var CameraObject : Transform;

function OnMouseDown() {
	
	var MenuOptions = CameraObject.GetComponent(MainCamera);
	
	MenuOptions.isLoading = true;

}

I know that it’s working because the ‘isLoading’ boolean is turned to true, as I can see in the Inspector, however the OnGUI function is not being called.

Try start a new Game with

var isLoading : false;

function OnMouseDown() {
    if(!isLoading){
    //  ...load your Menu
    }else{
    //	...unload your Menu
    }
    isLoading = !isLoading;
}